/*******************************************************************************
 * Copyright 2017 Bstek
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License.  You may obtain a copy
 * of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations under
 * the License.
 ******************************************************************************/
package com.bstek.urule.model.rete.builder;

import com.bstek.urule.RuleException;
import com.bstek.urule.model.rete.BaseReteNode;
import com.bstek.urule.model.rete.OrNode;
import com.bstek.urule.model.rule.lhs.BaseCriterion;
import com.bstek.urule.model.rule.lhs.Criterion;
import com.bstek.urule.model.rule.lhs.Or;

import java.util.ArrayList;
import java.util.List;

/**
 * @author Jacky.gao
 * @since 2016年9月9日
 */
public class OrBuilder extends JunctionBuilder {
    @Override
    public BaseReteNode buildCriterion(BaseCriterion c, BuildContext context) {
        Or or = (Or) c;
        List<Criterion> criterions = or.getCriterions();
        if (criterions == null || criterions.size() == 0) {
            throw new RuleException("Condition join node[or] need one child at least.");
        }
        List<BaseReteNode> childNodes = new ArrayList<BaseReteNode>();
        for (Criterion criterion : criterions) {
            BaseReteNode node = buildCriterion(criterion, context, null);
            if (node == null) {
                continue;
            }
            childNodes.add(node);
        }
        if (childNodes.size() == 0) {
            return null;
        }
        if (childNodes.size() == 1) {
            return childNodes.get(0);
        }
        OrNode orNode = new OrNode(context.nextId());
        for (BaseReteNode node : childNodes) {
            node.addLine(orNode);
        }
        return orNode;
    }

    @Override
    public boolean support(Criterion criterion) {
        return criterion instanceof Or;
    }
}
